Nonlinear dynamic modeling and decoupling for rigid–flexible coupled system of spacecraft with rapid maneuver

Abstract

In this paper, the rigid–flexible coupled model of a spacecraft composed of a rigid platform and two flexible solar arrays is investigated. Considering the rapid maneuver of a spacecraft, the first-order approximation coupling model should be adopted. The nonlinear dynamic equations, which remain the second-order coupling terms of axial displacement caused by the transverse motion of solar arrays, are obtained by using the Hamilton principle. Then the global mode method is adopted to obtain the mode shapes of the linearized model. The global mode shapes are proved to be orthogonal and used to discrete the continuum first-order approximation coupling model. Then the rigid–flexible coupled model of the spacecraft is decoupled by global mode shapes. The model is validated by comparing with that obtained from the finite element method. The simulation results demonstrate that the global mode method has the advantage of lower dimensions but higher accuracy. The analysis of parameters variation and dynamic responses shows that the first-order approximation coupling model is more accurate than the linearized model and has a broader scope of application than that of the zero-order approximation coupling model.